1. Field of the invention
This invention relates to a liquid detergent composition, more particularly to a liquid detergent composition for cleaning food, dinnerware, and kitchen utensils.
2. Description of the related art
Food, such as vegetables and fruits, are normally contaminated with pollutants, such as pesticides, fertilizers, preservatives, bacteria, dirt, etc., and has to be rinsed before serving or cooking. Dinnerware or kitchen utensils also have to be cleaned after use prior to storage.
Commercially available detergents for cleaning food, dinnerware, or kitchen utensils are mainly classified into two classes of detergents namely petrochemical surfactant-based detergents, such as alkyl-benzene sulfonated surfactants, and coconut oil-based detergents. The coconut oil of the coconut oil-based detergents can be derived from coconut oil, coconut oil alcohol, or coconut oil aliphatic acid derivatives.
An example of the petrochemical surfactant-based detergents was described in U.S. Pat. No. 4,140,649, which disclosed a non-toxic and hypotonic composition to be added to washwater to eliminate contaminants and pollutants from the surfaces of food and fodder. A portion of the above described composition contains 1 to 10 wt % of sulfate or sulfonate compounds.
While petrochemical surfactant-based detergents can provide a good cleansing action, such detergents tend to adhere to the surfaces of washed objects, such as food, dinnerware, or the kitchen utensils, after washing, and are not easily removed with water. As such, they may cause health problem if they enter the human body via these objects. In addition, waste water due to use of this type of detergents may result in significant pollution to the environment.
An example of the coconut oil-based detergents was described in U.S. Pat. No. 4,808,330, which disclosed a non-toxic detergent composition for effectively removing pollutants such as residual toxicities, bacteria, and fungi, from food surfaces. A portion of the above described composition contains from 8 to 25 wt % of coconut oil.
While the coconut oil-based liquid detergent composition described in U.S. Pat. No. 4,808,330 may be less harmful to the human body and to the environment as compared to the petrochemical surfactants-based detergents, the coconut oil used in such a composition is immiscible with water, and requires addition of a large amount of alcohol to emulsify coconut oil in water. Since the thus obtained liquid detergent is present as an emulsion, and does not have a transparent appearance, it is not suitable for acceptance as a commercial product by consumers. Moreover, the sodium chloride used as a buffering medium for stabilizing the coconut oil and the alcohol in the above described detergent composition has an adverse effect on the aroma of foods upon cleaning.